1. Field of the Invention
The invention concerns an assembly for the separation of blood into its component light liquid and heavy, substantially cellular phases under centrifugal force.
2. Brief Description of the Prior Art
It is known to separate blood into its component parts by centrifugation, for example, the assembly disclosed in U.S. Pat. No. 2,460,641. However, this particular assembly does not employ a means for sealing the separated plasma or serum phase from the cellular phase.
It is also known to provide assemblies for manually separating the plasma or serum phase from the cellular phase, for example, as disclosed in U.S. Pat. Nos. 3,586,064; 3,661,265; 3,355,098, 3,481,477; 3,512,940; and 3,693,804. In all of these devices the serum is collected in a blood collection container and means are provided for separating the plasma or serum phase from the cellular phase employing filters, valves, transfer tubes or the like.
It is also known to provide assemblies for the sealed separation of blood in which a piston is actuated by centrifugal force such as is disclosed in U.S. Pat. Nos. 3,508,653 and 3,779,383. These devices use either a compressible piston made of resilient material or valve means associated with the piston to effect a sealed separation after centrifugation. It is also known that a liquid sealant can be used for the separated portions of a blood sample as is covered by U.S. Pat. No. 3,780,935, but such patent does not disclose the piston for squeezing out the sealant of the present invention.